JP2022095258A - Manuscript transfer device, image reader and image forming apparatus - Google Patents

Abstract

To provide a manuscript transfer device that can easily take out a manuscript on a discharge tray even if a supply tray has a configuration that lifts.SOLUTION: A manuscript transfer device 16 of the invention includes: a discharge tray 37 disposed below a supply tray 36; a transfer unit 38 for discharging a manuscript M on the supply tray 36 from a discharge part 45 to the discharge tray 37; and a lifting part 50 that lifts the supply tray 36 and the discharge part 45. The lifting part 50 elevates the supply tray 36 and the discharge part 45 in response to the delivery of the manuscript M, and in a multi-discharge state in which the height of the manuscript M stacked on the discharge tray 37 is equal to or greater than a specified value (F), the lifting part 50 positions the supply tray 36 upward from the uppermost manuscript M at a predetermined interval G, and in a low-discharge state ST2 in which the height of the manuscript M is less than the specified value (F), the lifting part 50 positions the supply tray 36 at a take-out position P1 with the predetermined interval G from the top-most manuscript M when the height of the manuscript M is assumed to be the specified value (F).SELECTED DRAWING: Figure 7

Description

The present invention relates to a document transporting device, an image reading device, and an image forming device.

There is known a document feeder that ejects original documents one by one from a bundle of originals placed on a paper feed tray to an output tray for originals (Patent Document 1). This document feeder is provided with an elevating mechanism that sequentially raises the paper feed tray from the lowest position according to the decrease in the thickness dimension of the document bundle on the paper feed tray. By making the paper feed tray up and down, the number of originals placed on the paper feed tray can be increased.

Japanese Unexamined Patent Publication No. 2005-8283

In the document feeder described above, after the transfer of documents is completed, the raised paper feed tray is lowered to the extent that it does not interfere with the documents on the document output tray. Therefore, when the amount of original paper on the original paper output tray is small, the paper feed tray is lowered to the vicinity of the lowest position. Then, since the space between the paper feed tray and the original paper output tray becomes narrower, it becomes difficult for the user to put his / her hand in, and it becomes difficult to take out the original material ejected to the original paper output tray.

In order to solve the above problems, the present invention provides a document transporting device, an image reading device, and an image forming device that can easily take out a document on an ejection tray even if the supply tray moves up and down. do.

In the document transport device of the present invention, a supply tray for loading documents, an ejection tray arranged below the supply tray, and the documents on the supply tray are fed one by one to the document transfer path, and the document transfer path. The elevating unit includes a transport unit that ejects the document that has passed through the ejection section to the ejection tray, and an elevating section that raises and lowers the supply tray and the ejection section. The elevating and lowering is performed in a multi-ejection state in which the supply tray and the ejection unit are raised, the original document is fed to the original document transport path, and the height of the original document loaded on the ejection tray is equal to or higher than a specified value. The unit arranges the supply tray at a height above the top-level document at a predetermined interval, finishes feeding the document to the document transport path, and loads the document on the discharge tray. In a low discharge state where the height is less than the specified value, the elevating part supplies the original to the ejection position at a predetermined interval from the highest-ranked original when the height of the original is assumed to be the specified value. Place the tray.

In this case, the elevating part is provided in the supply tray, and is provided in the first detection part for detecting the distance between the uppermost original document loaded on the discharge tray and the supply tray, and the discharge part. It has a second detection unit that detects the number of documents to be ejected to the ejection tray, and a third detection unit that is provided in the transport unit and detects the supply tray arranged at the ejection position. The elevating unit determines a high discharge state or a low discharge state based on the detection result of the second detection unit, and in the high discharge state, the elevating unit is based on the detection result of the first detection unit. The height of the supply tray may be controlled, and in the low discharge state, the elevating unit may control the height of the supply tray based on the detection result of the third detection unit.

In other cases, the elevating part is provided in the supply tray, and is provided in the first detection part for detecting the distance between the uppermost original document loaded on the discharge tray and the supply tray, and the transport part. The elevating part has a height detecting part for detecting the height of the discharging part and a third detecting part for detecting the supply tray provided in the transporting part and arranged at the taking-out position. The high discharge state or the low discharge state is determined based on the detection result of the height detection unit, and in the high discharge state, the elevating unit raises and lowers the supply tray based on the detection result of the first detection unit. In the low discharge state, the elevating unit may control the height of the supply tray based on the detection result of the third detection unit.

In this case, the ejected document detecting unit for detecting the document loaded on the eject tray is further provided, and when the ejected document detecting unit detects the document, the elevating unit sets the supply tray to the ejecting position. When the ejected original detection unit that has detected the original is no longer detecting the original, the elevating portion lowers the supply tray to the lowest position and lowers the ejecting portion. It may be lowered to the lowest position.

The image reading device of the present invention includes any of the above-mentioned document transporting devices and a reading unit that reads an image on the document that is transported along the document transport path by the transporting unit.

The image forming apparatus of the present invention includes the above-mentioned image reading apparatus.

According to the present invention, even if the supply tray is raised and lowered, the originals on the ejection tray can be easily taken out.

It is a schematic diagram (front view) which shows the internal structure of the image forming apparatus which concerns on one Embodiment of this invention. It is sectional drawing which shows the document transporting apparatus which concerns on 1st Embodiment of this invention. It is a block diagram which shows the control part of the document transporting apparatus which concerns on 1st Embodiment of this invention. FIG. 5 is a cross-sectional view showing a state in which a top-level document is pressed against a pickup roller in the document transport device according to the first embodiment of the present invention. It is sectional drawing which shows the state which moved the supply tray to the uppermost position in the document transporting apparatus which concerns on 1st Embodiment of this invention. It is a document transporting apparatus which concerns on 1st Embodiment of this invention, and is sectional drawing which shows the multi-discharge state. It is a document transporting apparatus which concerns on 1st Embodiment of this invention, and is sectional drawing which shows the small discharge state. It is a flowchart explaining the control of the elevating part of the document transporting apparatus which concerns on 1st Embodiment of this invention. FIG. 5 is a cross-sectional view showing a state in which a top-level document is pressed against a pickup roller in the document transport device according to the second embodiment of the present invention. It is a flowchart explaining the control of the elevating part of the document transporting apparatus which concerns on 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that L, R, U, and D shown in the drawing indicate left, right, top, and bottom, and the front side of the drawing is the front side. Although terms indicating directions and positions are used in the present specification, these terms are used for convenience of explanation and do not limit the technical scope of the present invention.

The image forming apparatus 1 will be described with reference to FIG. FIG. 1 is a schematic view (front view) showing the internal structure of the image forming apparatus 1.

[Overview of image forming equipment]
As shown in FIG. 1, the image forming apparatus 1 includes an image forming apparatus 1A and an image reading apparatus 1B. The image forming apparatus 1A is an apparatus for forming an image on the paper S by an electrophotographic method. The image reading device 1B is a device that optically reads the image of the document M and converts it into digital data. The image forming apparatus 1 is provided with a control unit 14 for appropriately controlling the image forming apparatus 1A and the image reading apparatus 1B.

[Image drawing device]
A paper feed cassette 3 for accommodating a bundle of paper S made of paper is detachably attached to the lower side of the device main body 2 of the image drawing device 1A. An output tray 4 for receiving the image-formed paper S is provided on the upper surface of the apparatus main body 2. The paper S is not limited to paper, and may be a resin film or the like.

The image forming apparatus 1A includes a paper feeding unit 5, an image forming unit 6, and a fixing unit 7 inside the apparatus main body 2. The paper feed unit 5 is provided on the upstream side of the transport path 8 extending from the paper feed cassette 3 to the paper output tray 4. The fixing section 7 is provided on the downstream side of the transport path 8, and the image forming section 6 is provided between the paper feed section 5 and the fixing section 7 in the transport path 8.

The image forming unit 6 includes an intermediate transfer belt 10, four image forming units 11, four toner containers 12, and an exposure unit 13. The four image forming units 11 are provided side by side in the left-right direction under the intermediate transfer belt 10. The exposure unit 13 is provided under each image forming unit 11. The four toner containers 12 are provided above the intermediate transfer belt 10 and contain toner (developer) for replenishment of four colors (yellow, magenta, cyan, black).

Each image forming unit 11 includes a photoconductor drum 20, a charging device 21, a developing device 22, a primary transfer roller 23, a cleaning device 24, and a static elimination device 25. Since the four image forming units 11 have the same configuration, one image forming unit 11 will be described below.

The photoconductor drum 20 is rotationally driven while being in contact with the intermediate transfer belt 10. The charging device 21, the developing device 22, the primary transfer roller 23, the cleaning device 24, and the static elimination device 25 are arranged around the photoconductor drum 20 in the order of the image forming process. The primary transfer roller 23 faces the photoconductor drum 20 with the intermediate transfer belt 10 interposed therebetween. The secondary transfer roller 26 is in contact with the right side of the intermediate transfer belt 10.

The control unit 14 has a storage unit 27 that stores (stores) programs, data, and the like, and an arithmetic processing unit 28 that executes arithmetic processing according to the program and the like (see FIG. 3). Various devices of the image forming apparatus 1 are electrically connected to the control unit 14, and the control unit 14 comprehensively controls the image forming apparatus 1.

[Image formation processing]
Here, the operation of the image forming apparatus 1A will be described. The image forming apparatus 1A forms an image on the paper S based on the image data read by the image reading apparatus 1B and the image data transmitted from an external terminal (personal computer or the like). The control unit 14 controls the image forming apparatus 1A based on the input image data, and the image forming process is executed as follows.

The charging device 21 charges the surface of the photoconductor drum 20. The exposure unit 13 exposes the photoconductor drum 20 to correspond to the image data, and forms an electrostatic latent image on the surface of the photoconductor drum 20. The developing device 22 develops an electrostatic latent image on the photoconductor drum 20 into a toner image using the toner supplied from the toner container 12. The four-color toner images carried on the four photoconductor drums 20 are sequentially primary-transferred to the intermediate transfer belt 10 by the primary transfer roller 23 to which the primary transfer bias is applied. As a result, a full-color toner image is formed on the surface of the intermediate transfer belt 10.

On the other hand, the paper feed unit 5 feeds the paper S in the paper feed cassette 3 to the transport path 8. The secondary transfer roller 26 secondarily transfers the toner image on the intermediate transfer belt 10 to the paper S passing between the intermediate transfer belt 10 and the paper S. The fixing unit 7 heat-fixes the toner image on the paper S. After that, the paper S is ejected to the output tray 4. The cleaning device 24 removes waste toner (residual toner) remaining on the surface of the photoconductor drum 20 after the primary transfer. The static elimination device 25 irradiates the static elimination light to remove the electric charge of the photoconductor drum 20.

[Image reader]
Next, the image reading device 1B will be described. As shown in FIG. 1, the image reading device 1B includes a reading unit 15 and a document transporting device 16. The reading unit 15 reads an image on the document M conveyed on the document transfer path 38A by the transfer unit 38 described later. The document transfer device 16 is arranged above the reading unit 15, and automatically feeds the documents M one by one to the document transfer surface 30A.

<Reading unit>
The reading unit 15 includes a contact glass 30, a platen glass 31, an optical scanning unit 32, a reflection unit 33, and an image sensor 34.

(Contact glass, platen glass)
The contact glass 30 is provided on the left side of the upper surface of the apparatus main body 2 and constitutes a document transport surface 30A through which the document M passes. The platen glass 31 is provided on the right side of the contact glass 30 and constitutes a document loading surface 31A for loading the document M.

(Optical scanning unit)
The optical scanning unit 32 stops at a position facing the document transport surface 30A and irradiates light toward the document M transported on the contact glass 30. Further, the optical scanning unit 32 irradiates the document M on the platen glass 31 (document loading surface 31A) with light while moving from the position facing the document transport surface 30A to the right in FIG.

(Reflective unit)
The reflection unit 33 reflects the light emitted from the optical scanning unit 32 and reflected by the document M toward the condenser lens 34A. When the optical scanning unit 32 irradiates the document M on the document loading surface 31A with light, the reflection unit 33 is the same as the optical scanning unit 32 so that the optical path length from the document M to the condenser lens 34A is always constant. Move in the direction.

(Image sensor)
The image sensor 34 is a semiconductor element that photoelectrically converts the light input through the condenser lens 34A. The condenser lens 34A is arranged coaxially with the light receiving portion of the image sensor 34. The image sensor 34 and the condenser lens 34A are fixed to the housing of the reading unit 15.

<Original transfer device>
Next, the document transfer device 16 according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 2 is a cross-sectional view showing the document transfer device 16.

As shown in FIG. 1, the document transfer device 16 includes a document holding unit 35, a supply tray 36, a discharge tray 37, and a transfer unit 38. In the following description, "upstream" and "downstream" refer to upstream and downstream in the transport direction of the document M.

(Original presser part)
The document pressing portion 35 includes a pressing portion main body 35A, a pressing member 35B, and a pressing plate 35C. The pressing portion main body 35A is formed so as to cover the respective glasses 30 and 31 of the reading portion 15. The pressing member 35B is provided on the lower surface of the pressing portion main body 35A so as to face the contact glass 30. The pressing plate 35C is provided on the lower surface of the pressing portion main body 35A so as to face the platen glass 31.

The pressing portion main body 35A is attached to the rear portion of the upper surface of the apparatus main body 2 of the image forming apparatus 1A via a hinge (not shown). The presser foot body 35A is provided so as to be rotatable (openable and closable) around the hinge. When the front side of the presser foot body 35A is lifted (opened), the contact glass 30 (document transport surface 30A) and the platen glass 31 (document loading surface 31A) are exposed. The pressing member 35B has a function of pressing the document M transported by the transport unit 38 against the document transport surface 30A. The presser plate 35C has a function of pressing the document M against the document loading surface 31A.

(Supply tray)
As shown in FIG. 2, the supply tray 36 is formed so as to extend diagonally upward to the right from the transport portion 38. The supply tray 36 is arranged at a position upward away from the presser foot main body 35A. Document M (bundle of document M) is loaded on the supply tray 36. The supply tray 36 has a downstream tray 36A arranged on the downstream side in the transport direction and an upstream tray 36B arranged on the upstream side in the transport direction.

The downstream tray 36A is provided with a pair of cursors 36C for aligning the front and rear ends of the loaded document M and aligning the center in the width direction of the document M with the center in the width direction of the supply tray 36. The downstream tray 36A is provided with a supply document detection unit 55 that detects whether or not the document M is placed on the supply tray 36. The feed document detection unit 55 is composed of, for example, a reflection type optical sensor, and is connected to the control unit 14 via a predetermined circuit (not shown). The upstream tray 36B is swingably connected to the upstream end of the downstream tray 36A. When the user flips up the upstream tray 36B as needed, the space above the discharge tray 37 is opened, and the document M can be easily taken out from the discharge tray 37.

(Discharge tray)
The discharge tray 37 is arranged below the supply tray 36 and above the document holding portion 35. Specifically, the upper surface of the presser foot body 35A arranged on the platen glass 31 is configured as the discharge tray 37 (see also FIG. 1). The discharge tray 37 receives the original document M that has been transported to the transport unit 38 and discharged. The ejection tray 37 is provided with an ejection document detecting unit 56 for detecting the document M loaded on the ejection tray 37. The output document detection unit 56 is composed of, for example, a reflection type optical sensor, and is connected to the control unit 14 via a predetermined circuit (not shown). The supply document detection unit 55 and the output document detection unit 56 described above are not limited to the reflective optical sensor, but may be a camera, a micro switch, or the like.

(Transport section)
As shown in FIG. 1, the transport portion 38 is provided on the left side of the presser portion main body 35A. Inside the transport unit 38, a substantially U-shaped document transport path 38A is formed so as to connect the supply tray 36 to the discharge tray 37. The transport unit 38 feeds the document M on the supply tray 36 one by one to the document transport path 38A, and ejects the document M that has passed through the document transport path 38A from the ejection section 45 to the ejection tray 37.

As shown in FIG. 2, a transport mechanism unit 40 that supports the transport mechanism is provided inside the transport unit 38. The pickup roller 41, the feed belt 42A, the separation roller 42B, the resist roller pair 43, and the transport roller 44 are rotatably supported around the axis in the transport mechanism section 40. Further, the transport mechanism section 40 is provided with a discharge section 45 that constitutes a downstream end portion of the document transport path 38A. A discharge roller pair 47 is rotatably supported around the axis of the discharge portion 45. In the resist roller pair 43 and the discharge roller pair 47, one roller is rotationally driven and the other roller is driven to rotate.

The pickup roller 41 is arranged above the upstream end of the document transport path 38A, and after coming into contact with the uppermost document M, is rotationally driven to send the document M to the document transport path 38A. The feed belt 42A and the separation roller 42B are provided on the downstream side of the pickup roller 41. The separation roller 42B comes into contact with the feed belt 42A from below, and the document M sent out by the pickup roller 41 is conveyed while being sandwiched between the feed belt 42A and the separation roller 42B. Even if two or more original documents M are pulled out by the pickup roller 41, the conveying speed of the original documents M other than the uppermost document M decreases due to the frictional force with the separation roller 42B, and the uppermost original document M is conveyed in advance. .. That is, the separation roller 42B or the like prevents the document M from being double-fed. The resist roller pair 43 is provided on the downstream side of the separation roller 42B and the like, and the transfer roller 44 is provided on the downstream side of the resist roller pair 43 and on the upstream side of the contact glass 30 (document transfer surface 30A).

The ejection unit 45 has a transport guide 46 that constitutes a document transport path 38A on the downstream side of the contact glass 30. The discharge roller pair 47 is provided at the downstream end of the transport guide 46. The upstream end of the transport guide 46 is supported so as to be swingable in the vertical direction with the swing shaft 48 as a fulcrum. The swing shaft 48 is also used as a rotation shaft of the driven roller 44A in contact with the transport roller 44.

[Image reading process]
Here, the operation of the image reading device 1B will be described with reference to FIGS. 1 and 2. The manuscript M set on the supply tray 36 is formed in the shape of a sheet of sheets. On the other hand, the manuscript M loaded on the platen glass 31 (manuscript loading surface 31A) is not limited to a sheet shape, but may be a booklet, a card, or the like.

First, a case where the document M is set in the supply tray 36 with the presser body 35A (document presser 35) closed will be described. When the user sets the document M (or a bundle of documents M) in the supply tray 36 and inputs a reading instruction, the control unit 14 controls the image reading device 1B, and the image scanning process is executed as follows.

The pickup roller 41 feeds the document M set in the supply tray 36 to the document transport path 38A, and the feed belt 42A and the separation roller 42B feed the document M downstream one by one. The resist roller pair 43 adjusts the timing at which the document M is sent out to the contact glass 30 (document transport surface 30A). The transport roller 44 is rotationally driven to feed the document M between the contact glass 30 and the pressing member 35B. The document M is conveyed while being pressed against the contact glass 30 (document transfer surface 30A) by the pressing member 35B. The optical scanning unit 32 irradiates the document M passing on the document transport surface 30A with light, and the light reflected by the document M is input to the image sensor 34 and converted into an electric signal. As a result, the image of the document M is read as image data. The discharge roller pair 47 feeds (discharges) the document M that has passed through the contact glass 30 (document transport surface 30A) to the discharge tray 37.

Next, a case where the document M is set on the platen glass 31 by opening the presser body 35A (document presser 35) will be described. When a reading instruction is input from the user, the optical scanning unit 32 irradiates the document M on the platen glass 31 (document loading surface 31A) with light while moving to the right. The light reflected by the document M is input to the image sensor 34 and converted into an electric signal, so that the image of the document M is read as image data.

The image data read as described above is stored in the storage unit 27 of the control unit 14, and the control unit 14 executes the image forming process (printing) already described. The image data may be stored in an external terminal without being printed.

[Elevating part]
The document transport device 16 includes an elevating section 50 that raises and lowers the supply tray 36 and the ejection section 45 according to the thickness (height) of the bundle of documents M loaded on the supply tray 36. By raising and lowering the supply tray 36 and the discharge unit 45, a large amount of document M can be loaded on the supply tray 36, and a large amount of document M can be discharged to the discharge tray 37. Hereinafter, the elevating portion 50 of the document transporting device 16 will be described with reference to FIGS. 2 and 3. FIG. 3 is a block diagram showing a control unit 14 and the like of the document transfer device 16.

As shown in FIG. 2, the elevating unit 50 includes an elevating mechanism 51, a first detection unit 52, a second detection unit 53, a third detection unit 54, and a control unit 14 (see FIG. 3). is doing. The control unit 14 is a component of the image forming apparatus 1, but is also a component of the elevating unit 50.

<Elevating mechanism>
The elevating mechanism 51 has a function of interlocking the supply tray 36 and the discharging portion 45 to elevate and lower the same amount. The elevating mechanism 51 raises and lowers the supply tray 36 and the discharge portion 45 between the lowest position (see FIG. 2) and the uppermost position (see FIG. 5). As shown in FIG. 2, the elevating mechanism 51 includes a rack 60, a pinion 61, an elevating motor 62, and a link member 63. The rack 60, the pinion 61, and the link member 63 are provided in pairs on both the front and rear sides of the transport mechanism portion 40, but only one of them is shown in the drawings.

The rack 60 is fixed to a side portion of a frame (not shown) of the transport mechanism portion 40. The pinion 61 is rotatably supported around the axis on the side of the downstream tray 36A. The pair of left and right pinions 61 are connected by a shaft (not shown). One pinion 61 is connected to the output shaft of the elevating motor 62 via a power transmission mechanism such as a gear train. For example, the rack 60 is formed in a substantially inverted U shape having internal teeth, and the pinion 61 meshes with the internal teeth of the rack 60. The elevating motor 62 is electrically connected to the control unit 14 via a drive circuit (not shown). The pinion 61 is rotationally driven by the elevating motor 62 and moves in the vertical direction while engaging with the rack 60.

The link member 63 is erected between the discharge portion 45 and the downstream tray 36A. Specifically, the link member 63 is erected between the end of the roller above the discharge roller pair 47 and the downstream tray 36A and the side. The upper and lower ends of the link member 63 are rotatably supported by a rotating shaft of the roller and a connecting shaft projecting from the downstream tray 36A.

<First detector>
The first detection unit 52 is composed of, for example, a reflection type light sensor (distance sensor) and is provided on the supply tray 36. Specifically, the first detection unit 52 is provided on the lower surface of the downstream tray 36A with the light emitting unit and the light receiving unit facing downward. The first detection unit 52 detects the distance between the top-level document M loaded on the discharge tray 37 and the supply tray 36.

<Second detector>
The second detection unit 53 is provided at the downstream end of the discharge unit 45. The second detection unit 53 includes a swing member 65 and a swing detection unit 66.

The swing member 65 is formed in a rod shape, and one end of the swing member 65 is rotatably supported by the swing detection unit 66. The rocking member 65 is arranged so as to be in contact with the document M discharged from the discharge unit 45. The rocking member 65 is pushed by the ejected document M and lifted, and after passing through the document M, falls under its own weight (returns to its original position). The rocking detection unit 66 is, for example, a transmissive optical sensor having a light emitting unit and a light receiving unit arranged with the rocking member 65 interposed therebetween. The rocking member 65 described above is provided at a position that blocks the optical path from the light emitting portion to the light receiving portion in the initial state, and is removed from the optical path when it is lifted by the ejected document M. That is, the swing detection unit 66 detects that the document M has passed through the ejection unit 45 by receiving the light from the light emitting unit at the light receiving unit. In other words, the second detection unit 53 detects the number of documents M ejected to the ejection tray 37. One end of the swing member 65 may be rotatably supported by the rotation shaft of the roller. Further, the rocking member 65 may be provided so as to block the optical path when it is removed from the optical path in the initial state and is lifted by the document M to be ejected. Then, the swing detection unit 66 may detect that the document M has passed through the discharge unit 45 by being shielded from light by the swing member 65.

<Third detector>
The third detection unit 54 is composed of, for example, a transmissive optical sensor, and is provided in the transport unit 38 (frame of the transport mechanism unit 40). The third detection unit 54 is arranged at an intermediate portion between the lowest position and the uppermost position of the supply tray 36. Although the details will be described later, when the supply tray 36 is arranged at the take-out position P1 set between the lowest position and the uppermost position, the light-shielding member 36D projecting from the downstream end of the supply tray 36 detects the third. It is arranged between the light emitting unit and the light receiving unit of the unit 54. The third detection unit 54 detects that the supply tray 36 is arranged at the take-out position P1 by blocking the light from the light emitting unit. The shape of the light-shielding member 36D may be deformed so that the light-receiving portion receives the light from the light-emitting portion when the supply tray 36 is arranged at the take-out position P1 (not shown).

As shown in FIG. 3, the first detection unit 52, the second detection unit 53 (swing detection unit 66), and the third detection unit 54 are electrically connected to the control unit 14 via a control circuit or the like, respectively. It is connected. The detection results (electrical signals) of the detection units 52 to 54 are sent to the control unit 14.

[Control of elevating part]
Next, the control of the elevating unit 50 will be described with reference to FIGS. 2, 4 to 8. FIG. 4 is a cross-sectional view showing a state in which the uppermost document M is pressed against the pickup roller 41. FIG. 5 is a cross-sectional view showing a state in which the supply tray 36 is moved to the uppermost position. FIG. 6 is a cross-sectional view showing a multi-discharge state ST1. FIG. 7 is a cross-sectional view showing a low discharge state ST2. FIG. 8 is a flowchart illustrating control of the elevating unit 50.

First, in the initial state before loading (setting) the document M on the supply tray 36, the supply tray 36 and the discharge unit 45 are arranged at the lowest positions (see FIG. 2). The document transfer device 16 is provided with a sensor (not shown) for detecting that the supply tray 36 (or the discharge unit 45) is arranged at the lowest position, so that the supply tray 36 and the like stop at the lowest position. Is controlled by. The supply tray 36 arranged at the lowest position can, for example, load up to 500 sheets of original M (plain paper). The maximum number of documents M that can be loaded on the supply tray 36 can be freely changed.

<Control of the elevating part during image reading processing>
When the supply document detection unit 55 detects that the document M is placed on the supply tray 36 and the user inputs a reading instruction for the document M, the control unit 14 drives the elevating motor 62 to lower the supply tray 36. The control of raising the original document M from the position and pressing the uppermost document M against the pickup roller 41 is executed (see FIG. 4). After that, the image reading process already described is executed. Whether or not the uppermost document M is pressed against the pickup roller 41 is detected by an upper limit detection switch (not shown) provided in or near the pickup roller 41. Further, the detection signal of the upper limit detection switch is monitored by the control unit 14 while the document M loaded on the supply tray 36 is fed. Further, in conjunction with the rise of the supply tray 36, the discharge portion 45 rotates upward around the swing shaft 48 and rises from the lowest position.

The elevating part 50 (elevating mechanism 51) raises the supply tray 36 and the discharging part 45 according to the feeding of the document M (see the white arrow and the thick arrow shown in FIG. 4). That is, when the document M is fed out and the thickness of the bundle of documents M becomes thin (low), the control unit 14 controls to raise the supply tray 36 until the upper limit detection switch detects the document M. The control unit 14 controls to gradually raise the supply tray 36 until all the documents M set in the supply tray 36 are fed out (until the supply document detection unit 55 stops detecting the document M) (see FIG. 5). ). Further, the second detection unit 53 detects the document M ejected from the ejection unit 45 to the ejection tray 37, and the control unit 14 integrates the detection results of the second detection unit 53 (the number of ejected documents M). Is stored in the storage unit 27.

When the feeding of the document M to the document transport path 38A is completed (the supply document detection unit 55 no longer detects the document M) and the second detection unit 53 detects the ejection of the last document M, the image reading process ends. (See FIG. 5). At the end of the image reading process, the supply tray 36 is arranged at the uppermost position (or near the uppermost position) (see FIG. 5). Further, the document transport device 16 is provided with a sensor for detecting that the supply tray 36 is arranged at the uppermost position (not shown), and the supply tray 36 is controlled to stop at the uppermost position.

<Control of the elevating part after the image reading process is completed>
After the image reading process is completed, the control unit 14 estimates the height of the document M loaded on the ejection tray 37 from the detection result (number of documents M) of the second detection unit 53. Specifically, the control unit 14 (elevating unit 50) determines the high discharge state ST1 or the low discharge state ST2 based on the detection result of the second detection unit 53. Here, the multi-discharge state ST1 refers to a state in which the height of the document M loaded on the discharge tray 37 is equal to or higher than the specified value (F). The low discharge state ST2 refers to a state in which the height of the document M loaded on the discharge tray 37 is less than the specified value (F). Further, the "specified value (F)" refers to, for example, the height when 320 original sheets M are stacked, and this specified value (F) is experimentally obtained in advance in the storage unit 27. It is remembered. Therefore, as shown in FIG. 8, the control unit 14 compares the number of documents M stored in the storage unit 27 with the specified value (F) based on the detection result of the second detection unit 53 (step S1). The number of documents M showing the specified value (F) is not limited to 320, and can be freely set according to, for example, the maximum distance between the supply tray 36 and the discharge tray 37.

When the multiple ejection state ST1 (the number of original documents M ≥ the specified value (F)) (YES in S1), the control unit 14 (elevating unit 50) has a height with a predetermined interval G above the uppermost original document M. The supply tray 36 is arranged (step S2). Specifically, the control unit 14 drives the elevating motor 62 and lowers the supply tray 36 until the first detection unit 52 detects the predetermined interval G (see FIG. 6). When the first detection unit 52 detects the predetermined interval G, the control unit 14 stops the elevating motor 62. That is, in the high discharge state ST1, the elevating unit 50 controls the height of the supply tray 36 based on the detection result of the first detection unit 52. The predetermined interval G is a gap such that the supply tray 36 does not come into contact with the uppermost original M, for example, a gap of about several mm to several tens of mm. Further, when 500 sheets of the original M are ejected, the supply tray 36 may be held at the uppermost position without being lowered. That is, with 500 documents M loaded on the ejection tray 37, there is a predetermined interval G (or more) between the top-level document M and the supply tray 36 arranged at the top position. It's open.

On the other hand, when the small ejection state ST2 (the number of original sheets M <specified value (F)) (NO in S1), the control unit 14 (elevating unit 50) sets the height of the original document M to the specified value (F). The supply tray 36 is arranged at the take-out position P1 at a predetermined interval G from the uppermost document M when it is assumed that the above is true (step S3). Specifically, the control unit 14 drives the elevating motor 62 and lowers the supply tray 36 until the third detection unit 54 detects the light-shielding member 36D (blocks the optical path) (see FIG. 7). When the third detection unit 54 detects the light-shielding member 36D, the control unit 14 stops the elevating motor 62. That is, in the low discharge state ST2, the third detection unit 54 detects the supply tray 36 arranged at the take-out position P1, and the elevating unit 50 determines the height of the supply tray 36 based on the detection result of the third detection unit 54. Control. The take-out position P1 (height of the supply tray 36 when the height of the document M is assumed to be the specified value (F)) is defined as the space between the supply tray 36 and the discharge tray 37. It is a position that can be easily touched and can be obtained experimentally. Further, the height of the supply tray 36 in the multi-discharge state ST1 is set to a height equal to or higher than the take-out position P1.

In the multi-discharge state ST1, the bundle of documents M loaded on the discharge tray 37 is thick (high), so that the distance between the supply tray 36 and the discharge tray 37 is sufficiently widened (see FIG. 6). Therefore, the user can easily take out the document M by putting a hand between the supply tray 36 and the discharge tray 37. On the other hand, in the case of the low discharge state ST2, the supply tray 36 is held at least at the height (ejection position P1) when the height of the document M is the specified value (F), so that the user can use the supply tray 36. It is easy to put a hand between the and the discharge tray 37 (see FIG. 7). Therefore, the user can easily take out the document M.

Next, the control unit 14 determines the presence or absence of the document M on the ejection tray 37 based on the detection result of the ejected document detecting unit 56 (step S4). When the document M is on the ejection tray 37 (YES in S4), the control unit 14 (elevating section 50) sets the supply tray 36 at the ejection position P1 or higher. That is, the control unit 14 does not drive the elevating motor 62 and holds the supply tray 36 at the current position.

When the ejected document detecting unit 56 that has detected the document M no longer detects the document M (NO in S4), the control unit 14 (elevating unit 50) lowers the supply tray 36 to the lowest position and ejects the document M. 45 is lowered to the lowest position (step S5). Specifically, the control unit 14 drives the elevating motor 62 to lower the supply tray 36 to the lowest position. Further, the discharge unit 45 descends to the lowest position in conjunction with the descent of the supply tray 36. As a result, the supply tray 36 and the discharge unit 45 are arranged at the lowest position (see FIG. 2).

In the document transport device 16 according to the first embodiment described above, in the low discharge state ST2, the elevating unit 50 determines the height of the document M from the highest document M on the assumption that the height is the specified value (F). The supply tray 36 is arranged at the take-out position P1 with an interval G. According to this configuration, even if the amount of the ejected document M is small, the lowering of the supply tray 36 can be restricted. As a result, even if the supply tray 36 has a structure that moves up and down, a small amount of the document M on the discharge tray 37 can be easily taken out.

Further, according to the document transport device 16 according to the first embodiment, the height of the document M can be estimated by the second detection unit 53 detecting the number of documents M loaded on the ejection tray 37. , It is possible to accurately determine which state S1 or S2 is in the discharge tray 37. Further, the first detection unit 52 detects the distance between the uppermost document M and the supply tray 36, so that the supply tray 36 can be arranged at a position where the uppermost document M does not come into contact with the supply tray 36. Further, by moving the supply tray 36 so that the third detection unit 54 detects the supply tray 36, the supply tray 36 can be arranged at the take-out position P1.

Further, according to the document transport device 16 according to the first embodiment, while the document M is loaded on the eject tray 37, the eject document detection unit 56 continues to detect the document M, so that the supply tray 36 is ejected from the eject tray. The document M can be easily taken out from the ejection tray 37 by separating it from the 37. On the other hand, when the document M is taken out from the ejection tray 37, the ejected document detecting unit 56 does not detect the document M, so that the supply tray 36 and the like can be returned to the lowest position. As a result, the next document M can be set in the supply tray 36.

[Second Embodiment]
Next, the document transfer device 17 according to the second embodiment will be described with reference to FIGS. 9 and 10. FIG. 9 is a cross-sectional view showing a state in which the uppermost document M is pressed against the pickup roller 41. FIG. 10 is a flowchart illustrating control of the elevating unit 50. Hereinafter, the same configuration (or corresponding configuration) as the document transporting device 16 according to the first embodiment is designated by the same reference numerals, and the description of the same or corresponding to the document transporting device 16 will be omitted.

As shown in FIG. 9, in the document transport device 17 according to the second embodiment, the elevating section 50 has a height detecting section 57 provided in the transport section 38 (frame of the transport mechanism section 40). The height detection unit 57 is composed of, for example, a transmissive optical sensor, and detects the height of the discharge unit 45. The height detection unit 57 is electrically connected to the control unit 14 via a control circuit or the like, and the control unit 14 receives the detection result (electric signal) of the height detection unit 57. Further, the document transfer device 17 according to the second embodiment also includes a second detection unit 53.

Specifically, the height detection unit 57 is a discharge unit 45 (when the supply tray 36 rises from the lowest position and the uppermost document M is pressed against the pickup roller 41 at the start of the image reading process. The height of the transport guide 46) is detected. When the document M of less than 320 sheets is set in the supply tray 36, the ejection unit 45 (transport guide 46) is arranged between the light emitting unit and the light receiving unit of the height detecting unit 57 at the start of the image reading process, and emits light. Light is blocked from the part. Upon receiving the detection result of the height detecting unit 57, the control unit 14 estimates that less than 320 documents M set in the supply tray 36 are ejected to the ejection tray 37. The detection result of the height detection unit 57 is stored in the storage unit 27. In addition, when the document M of less than 320 sheets is set in the supply tray 36, the discharge unit 45 may be provided with a light-shielding member so as to be separated from the light-emitting unit and the light-receiving unit of the height detection unit 57. Not shown).

<Control of the elevating part after the image reading process is completed>
As shown in FIG. 10, after the image reading process is completed, the control unit 14 (elevating unit 50) is in a multi-discharge state based on the detection result of the height detection unit 57 (detection result stored in the storage unit 27). The ST1 or the low discharge state ST2 is determined (step S1'). That is, when the height detection unit 57 has not detected the discharge unit 45 (NO in step S1'), the control unit 14 determines that the multi-emission state ST1 is set, and the height detection unit 57 determines the discharge unit 45. If it has been detected (YES in step S1'), the control unit 14 determines that it is in the low discharge state ST2. Since the control step after step S1'is the same as the control of the elevating unit 50 of the document transport device 16 according to the first embodiment, the description thereof will be omitted.

According to the document transport device 17 according to the second embodiment described above, even if the ejected document M is a small amount, the lowering of the supply tray 36 is restricted, and the document M on the eject tray 37 can be easily taken out. It is possible to obtain the same effect as that of the document transport device 16 according to the first embodiment. Further, by detecting the height of the discharge unit 45 by the height detection unit 57, it is possible to accurately determine which state S1 or S2 is in the discharge tray 37.

In the document transporting devices 16 and 17 according to the first and second embodiments, the supply tray 36 and the discharge tray 37 are connected by the link member 63 so that they can be raised and lowered by the raising and lowering mechanism 51. , The present invention is not limited to this. The elevating unit 50 may separately include a mechanism for raising and lowering the supply tray 36 and a mechanism for raising and lowering the discharge tray 37 (not shown).

Further, in the document transporting devices 16 and 17 according to the first and second embodiments, the elevating mechanism 51 is a mechanism including the rack 60 and the pinion 61, but the present invention is not limited thereto. For example, the elevating mechanism may be a mechanism including a pulley and a wire, or a mechanism including a piston and a cylinder (not shown).

Further, in the document transporting devices 16 and 17 according to the first and second embodiments, the first detection unit 52 is a reflection type optical sensor, but the present invention is not limited to this, and for example, a laser range finder or an ultrasonic range finder is used. Etc. (not shown). Further, the second detection unit 53 includes a rocking member 65 that blocks the optical path of the rocking detecting unit 66, but the present invention is not limited to this. For example, the second detection unit 53 may include a micro switch pressed by the rocking member 65, or may be composed of only a sensor that optically detects the document M (not shown). Further, the third detection unit 54 is a transmissive optical sensor, but the present invention is not limited to this. For example, the third detection unit 54 may be a reflection type optical sensor that detects the supply tray 36 arranged at the take-out position P1, or is a micro switch pushed by the supply tray 36 arranged at the take-out position P1. May (not shown). Further, the height detection unit 57 is a transmissive optical sensor, but the present invention is not limited thereto. For example, the height detection unit 57 may be a reflective optical sensor that detects the discharge unit 45 that has risen to a predetermined position, or may be a microswitch that is pressed by the discharge unit 45 that has risen to a predetermined position. , An angle sensor or the like that detects the rotation angle of the discharge unit 45 may be used (not shown).

Further, in the document transport device 16 according to the first embodiment, the height of the document M on the ejection tray 37 is estimated by the second detection unit 53 detecting the number of documents M ejected to the ejection tray 37. In the document transport device 17 according to the second embodiment, the height detecting unit 57 detects the height of the ejection unit 45 to estimate the height of the document M on the ejection tray 37. Is not limited to this. For example, an optical sensor, an ultrasonic sensor, or the like that directly detects that the height of the document M loaded on the discharge tray 37 has reached the specified value (F) may be provided (not shown).

Further, in the document transporting devices 16 and 17 according to the first and second embodiments, the elevating unit 50 is controlled by the control unit 14 provided in the image forming apparatus 1, but the elevating unit is separate from the control unit 14. A dedicated control unit for controlling 50 may be provided (not shown).

Further, in the description of the present embodiment, the case where the present invention is applied to the image forming apparatus 1 (multifunction device) is shown as an example, but the present invention is not limited to this, and is not limited to this, for example, to a copying machine, a facsimile, an image reading-only machine, or the like. The present invention may be applied.

It should be noted that the description of the above embodiment shows one aspect of the document transporting apparatus, the image reading apparatus and the image forming apparatus according to the present invention, and the technical scope of the present invention is not limited to the above embodiment. do not have. The present invention may be variously modified, replaced or modified without departing from the spirit of the technical idea, and the claims include all embodiments that may be included within the scope of the technical idea.

1 Image forming device 1B Image reading device 15 Reading unit 16, 17 Document transporting device 36 Supply tray 37 Discharging tray 38 Conveying section 38A Document transport path 45 Discharging section 50 Elevating section 52 1st detection section 53 2nd detection section 54 3rd detection Part 56 Ejection document detection part 57 Height detection part G Predetermined interval P1 Extraction position ST1 Multi-ejection state ST2 Low-ejection state

Claims (6)

A supply tray for loading documents and
The discharge tray located below the supply tray and
A transport unit that feeds the documents on the supply tray one by one to the document transport path and ejects the documents that have passed through the document transport path from the ejection section to the ejection tray.
The supply tray and the elevating part for raising and lowering the discharging part are provided.
The elevating part raises the supply tray and the discharging part according to the feeding of the document.
In a multi-discharging state in which the feeding of the document to the document transport path is completed and the height of the document loaded on the ejection tray is equal to or higher than a specified value, the elevating portion moves upward from the top-level document. Place the supply tray at a height with a predetermined interval,
In a small ejection state where the feeding of the original to the document transport path is completed and the height of the original loaded on the ejection tray is less than the specified value, the elevating part sets the height of the original to the specified value. A document transporting device, characterized in that the supply tray is arranged at an extraction position at a predetermined interval from the top-level document when it is assumed that the above is true. The elevating part
A first detection unit provided on the supply tray and detecting the distance between the uppermost original document loaded on the discharge tray and the supply tray, and the like.
A second detection unit provided in the ejection unit and detecting the number of documents ejected in the ejection tray, and a second detection unit.
It has a third detection unit provided in the transport unit and detecting the supply tray arranged at the take-out position.
The elevating unit determines a large discharge state or a low discharge state based on the detection result of the second detection unit.
In the multiple discharge state, the elevating unit controls the height of the supply tray based on the detection result of the first detection unit.
The document transport device according to claim 1, wherein in the low discharge state, the elevating unit controls the height of the supply tray based on the detection result of the third detection unit. The elevating part
A first detection unit provided on the supply tray and detecting the distance between the uppermost original document loaded on the discharge tray and the supply tray, and the like.
A height detecting unit provided in the transport unit and detecting the height of the discharging unit,
It has a third detection unit provided in the transport unit and detecting the supply tray arranged at the take-out position.
The elevating part determines the high discharge state or the low discharge state based on the detection result of the height detection unit.
In the multiple discharge state, the elevating unit controls the height of the supply tray based on the detection result of the first detection unit.
The document transport device according to claim 1, wherein in the low discharge state, the elevating unit controls the height of the supply tray based on the detection result of the third detection unit. Further, an ejected document detecting unit for detecting the document loaded on the ejected tray is provided.
When the ejected document detecting unit detects the document, the elevating unit arranges the supply tray at a position equal to or higher than the ejection position.
When the ejected document detecting unit that has detected the document no longer detects the document, the elevating unit lowers the supply tray to the lowest position and lowers the ejecting unit to the lowest position. The document transport device according to any one of claims 1 to 3, wherein the document transport device is characterized. The document transporting apparatus according to any one of claims 1 to 4,
An image reading device including a reading unit that reads an image on the document that is transported along the document transport path by the transport unit. An image forming apparatus comprising the image reading apparatus according to claim 5.

Images